Adolescence is a period of the lifespan when challenges to behavioral regulation can have critical short and long-term repercussions including increased risk for substance abuse. To date, studies of the neural correlates of inhibitory control during this period have clear limitations and are thus poorly understood, representing a gap in knowledge with implications for a major public health concern. If we understood the mechanisms of inhibitory control, specifically in the face of rewarding stimuli, we could create more effective preventive interventions. Here we address this gap in the literature by introducing a novel test of inhibitory control over reward: Habitual Appetitive Behavior Inhibition Task (HABIT) and propose to investigate the neural correlates of the developmental progression of inhibitory control over reward in late childhood, early adolescence, late adolescence and adulthood using structural and functional magnetic resonance imaging. We further propose investigating the relationship between neural structure and function and self-reported substance use and abuse during adolescence. This task, relative to other assessments of inhibitory control, isolates deficits in adolescent cognition, relative to children that most closely aligns with the dramatic uptick in risk taking and self-reported impulsivity in adolescence